Here at home, it is game on for the more than 43 million americans hitting the road this holiday. Tomorrow could be the busiest travel day of the year. But thenksgiving migration has already begun, americans scrambling into planes, trains and automobiles. And abc's senior national correspondent jim avila starts us off. Reporter: Good evening, george. Tomorrow is supposed to be the busiest travel day of the year but airlines cut the number of flights down 3% and that means that if the weather holds it actually could be a pleasant week to travel everywhere but in a couple of spots. A twin threat to air travel on the west coast. Airport workers scheduled to demonstrate at los angeles international tomorrow afternoon, prompting warnings for passengers to give themselves a three-hour cushion at l.A.X. And an extra 90 minutes to get there. This is part of the fun of it all to go and fight the fight, to fight the crowds. Reporter: Up north, crippling rain in oregon and washington expected to delay northwest flights. But for the rest of the country, weather is on travel's side for a change. 75% of the country will be rain-free. Northwest, not so great, we will see heavy rains and mountain snows continuing. Reporter: And since seattle is not a major domestic hub, the ripple effect of bad weather there is unlikely to spread. If there were to be a storm in chicago or in the northeast, you could count on mass chaos, but that does not look like that is going to be the case at all. Reporter: There are some new 2012 holiday tricks for savvy travelers. Some airlines will allow you to avoid the baggage counter by tagging and checking your own bag, giving you the opportunity to lose your own luggage. Tsa has a new precheck program this year. Sign up, and you pass through a separate security line, with your laptop in your bag and your shoes on your feet. And there are new smartphone apps that monitor security lines, so you can back time your approach. Flights are full and rebooking a challenge. It's extremely important to know how much time you actually have to get to your gate so that you don't potentially miss your flight and get stuck at the airport for thanksgiving. Reporter: And one final tip, leave the cranberry sauce at home. Because of the tsa ban on liquids, your turkey is welcome, but the cranberries are on the no-fly list. Now to alex perez and the nation's highways where 90% of holiday travelers find themselves. Reporter: Well, jim, some 39 million motorists will be getting in their cars and hitting the roads this thanksgiving. And aaa says the best time to get behind the wheel is 7:00 a.M. Because by 5:00 p.M., The roads will already be jammed. Another tip, every state is part of the 511 traffic system. So before you head out remember to dial 511 for the latest traffic and road closures in your state. And drivers in the northeast prepare for a roadblock. If you're looking to rent a car, you're probably out of luck. Superstorm sandy has led to a shortage in rental cars. Your best bet may be the train and for the latest on the railways let's go to my colleague lisa stark in washington d.C. Lisa. Reporter: Amtrak is booming and tomorrow is the busiest day yesterday. 138,000 passengers crowded on board the day before thanksgiving last year. Now, here in the northeast amtrak has even borrowed trains from canada to handle the crush. Usually it relies on cars from new jersey's transit but many of those were damaged by hurricane sandy and that storm also means many of the commuter lines aren't up to speed. You should check the schedules online. And a bit of advice, get to the station at least 45 minutes early. Bring your i.D. And if you're on one of those long distance line, well, come hungry. There will be a full thanksgiving menu on board.

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